The primary objective of this contract shall be to provide support services for the Environmental Epidemiology Branch (EEB), Epidemiology & Biostatistics Program (EBP), Division of Cancer Etiology (DCE), National Cancer Institute (NCI), by continuing the follow-up of a cohort of DES-exposed individuals for the estimation of long-term cancer risk. In addition, specific sub-studies of non-cancer endpoints, using the resource of the combined cohort, shall be designed and conducted. The recommendations of the 1992 NIH workshop on DES shall be relied upon to form priorities for specific studies. A "Steering Committee" shall be formed to guide and coordinate future research efforts in the DES-exposed and comparison cohorts.